1. Field of the Invention
The present invention relates generally to computer modeling of waffle slabs, and particularly to a strut and tie method for waffle slabs providing a computerized method for the analysis and design of waffle slabs for the building and construction industries.
2. Description of the Related Art
Waffle slabs, also known as two-way ribbed flat slab, provide an economical and popular system in buildings and other types of structures. The waffle slab's increased rigidity compared to weight makes it economical for medium span structures. Also, interconnected ribs with a slab on the top ensures efficient lateral distribution of loads. They exhibit higher stiffness and small deflection. Waffle slab systems are commonly used in large auditoriums, parking garages, industrial facilities, marine structures and exhibition halls.
Problems with current design methods include the fact that the design methods neglect the existence of ribs and treat the slabs as solid slabs, and are approximate in nature. Finite element-based methods are also used for the design of waffle slabs. Conventional methods for the design of waffle slabs consider behavior for waffle slabs the same as flat plates or flat slabs. The effect of ribs, which are the primary load-carrying elements, is ignored in the analysis, and its effect on rigidity of the slab is arrived based on empirical formulae. Empirical methods currently being used do not predict the mode of failure of the waffle slab accurately. Instead, current methods restrict the parameters of the waffle, such as rib spacing, rib depth, rib thickness etc., to bring the slab in a desirable range where the empirical equations are more or less applicable.
Thus, a strut and tie method for waffle slabs solving the aforementioned problems is desired.